Mechanical time fuse



March 19, 1946. M. P. WHITNEY 2,397,065

' MECHANICAL TIME FUSE Filed Sept. 8, 1939 wiboesys I Y R' W 'ITORNEY.

Patented Mar. 19, 1946 S PATENT OFFICE MECHANICAL TIME FUSE Maurice 1. Whitney, Elmira, N. Y., assignor ito Bendix Aviation Corporation, SouthBend, Ind a corporation of Delaware Application September 8, 1939, Serial No. 293,991

2 Claims.

The present invention relates to a mechanical time fuse for explosive projectiles and more particularly to the means for controlling the trigger mechanism thereof.

In mechanical time fuses of the type in which a rotary disc is used to time the detonation of the charge, such, for instance, as illustrated in the patent to Junghans 1,693,516, a secondary setback of the disc sometimes occurs, which impairs the accuracy of the fuse.

Various structures have been employed to guard against this contingency by confining the disc against longitudinal distortion, but they have in general been subject to the objections of added complication and expense, and possible interference by friction or otherwise with the functioning of the fuse.

It is an object of the present invention to provide a novel mechanical time fuse which is effective and reliable in operation in spite of longitudinal accelerational or decelerational forces.

It is another object to provide such a device incorporating a timing member so formed as to resist the effects of longitudinal accelerational and decelerational forces.

It is a further object to provide such a device in which the timing member is so formed that longitudinal distortion thereof to a considerable degree cannot impair its accuracy.

Another object is to provide such a device incorporating means extraneous to the timing mechanism for positively limiting longitudinal distortion of the timing member.

Another object is to provide such a device in which the chamber for the timing mechanism is so formed as to cooperate with the timing member to positively limit longitudinal distortion thereof.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly broken away and in section of a portion of a shell case and nose incorporating a preferred embodiment of the present invention, the section being taken substantially along the line I--I of Fig. 2;

Fig. 2 is a section taken substantially on the line 2-2 of Fig. 1; and

Fig. 3 is a detail in perspective of the timing disc.

In Fig. 1 there is illustrated at I a portion of a shell case on which is swiveled a nose 2. The case I is provided with a seat or socket 3 for the reception of timing mechanism 4, and the nose 2 is provided with a recess or socket 5 cooperating with the seat 3 to house the timing mechanism i.

The timing mechanism comprises a dished timing disc 6 rotated by a friction clutch I from a shaft 8 of any suitable form of clockwork mechanism. Clutch 1 may be of any referred construction and is here shown as comprising a dished washer 1a clamping the timing disc against a flange lb on shaft 8 by virtue of a clamp nut 'Ic threaded on the end of said shaft.

According to the present invention, the timing disc 6 is provided with a cylindrical peripheral wall 9 terminating in a radial flange H. An opening I2 (Fig. 3) is formed in the wall *9 and the web of the disc in a definite angular relation to a forked arm I3 pressed up from said web. A trigger lever I4 which is arranged to control the detonation of the shell in any suitable manner, is provided with an arm I5 bearing on the surface of the wall 9 and arranged to enter the opening I2 therein when it comes into registry therewith.

Setting mechanism for the timing disc 6 is provided in the form of a pin I6 fixedly mounted in the bottom of the recess 5 in the nose 2 and projecting into proximity to the web of the disc in position to be received by the forked arm I3. Means are provided for disconnecting the setting mechanism upon discharge of the projectile in the form of a weight member II riveted as shown at 20 to a mounting spring I8 which is fixed as indicated at I9 in the bottom of the recess 5 of the nose. The weight member I! is arranged directly over the forked arm I3 straddling the pin I6, and when set back by the longitudinal acceleration of the projectile as it is fired, it flattens the forked arm I3 so as to prevent its engagement with said pin.

In order to positively limit distortion of the timing disc 6 to deflections which are substantially less than the height of the cylindrical wall 9, the base of the recess 5 in the nose is provided with an annular shoulder 2I which, when the parts are assembled, is in close proximity to the flange I I of the timing disc so as to positively prevent defiections of the disc due to deceleration or secondary setback efiects.

In operation, when it is desired to use the proiectile, the nose 2 is rotated with respect to the case I in order to set the timing disc 6 so that its opening I2 is a predetermined angular distance away from the trigger arm I5. It will be understood, of course, that this setting of the timing disc is accomplished by means of a suitable scale and pointer engraved on the nose and case of the shell,

Upon discharge of the shell, the weight member I1 is set back onto the forked arm l3, thus flattening it out and disengaging it from the pin l6 so that the timing disc 6 is free to rotate by the action of the timing mechanism 4.

When the timing disc 6 is rotated by the clockwork until the opening comes into registry with the arm l5 of the trigger, the trigger is released and thereupon permits detonation of the shell.

It will be readily appreciated that timing disc 6 is rendered highly resistant to longitudinal distortion by the formation of the cylindrical wall 9; I

Moreover, distortion of the disc in amounts less than the height of the wall cannot impair the accuracy of the fuse since the arm l5 of the trigger bears slidably on the outer surface of the wall.

explosive projectiles including a rotary timing disc having a cylindrical wall with an opening therein, said discalso having a continuous flange mounted thereon axially off-set from the body of the disc and extendingradially beyond the wall, means Distortion of the disc in amounts large enough to jeopardize the accuracy of the fuse is positively prevented by the shoulder 2| which limits the upward deflection of the disc by acting as an abutment for the flange H.

Although but one embodiment of the invention has been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In a mechanical time fuse for explosive projectiles, a trigger member and a clock-work mechanism for controlling the trigger member includ ing a rotary disc having a cylindrical peripheral mounted in the'fuse including a friction clutch 'for rotating the timing disc, and a trigger member pivotally mounted in the fuse having an arm bearing on said wall and adapted to enter said opening when the rotary disc has turned suiilciently to bring theopening into registry with the arm; and a shell providing a seat for the fuse, said shell having a rotatable nose piece, an axially mounted pin in the nose piece, said disc having a wall terminating in a radial flange oiT-set axially V flexible forked arm engaging the pm, said nose piece having a circular recess, a weight member in the recess operative when set back by discharge of the shell to disengage the forked arm from the pin, and said nose piece having a shoulder surrounding the recess'adjacent the cfi-set flange of the timing disc and adapted to limit the longi tudinal distortion of the timing disc to an amount substantially less thanrthe height of said cylindrical wall.

MAURICE P. WHI'I'NEY. 

